/**
 * Protocol routing reference data.
 *
 * This is generic, widely-published reference guidance (impedance targets, topology,
 * pull-up ranges) for common interconnects, not a precision electrical simulation. It
 * exists to give an agent a quick, citable starting point before laying out a bus —
 * always confirm against the current revision of the cited spec and your target
 * silicon's datasheet, since exact numbers vary by spec revision and vendor.
 *
 * @module
 */
export type ProtocolKey = 'usb2' | 'usb3' | 'rs485' | 'i2c' | 'spi' | 'uart' | 'ethernet-10-100' | 'ethernet-1000';
export interface ProtocolRoutingGuidance {
    protocol: ProtocolKey;
    displayName: string;
    topology: string;
    differentialImpedanceOhms?: number;
    singleEndedImpedanceOhms?: number;
    terminationOhms?: number;
    terminationNotes?: string;
    pullUpResistanceOhms?: {
        min: number;
        max: number;
    };
    lengthMatchingGuidance: string;
    maxRecommendedLengthNotes?: string;
    notes: string[];
    source: string;
    caveat: string;
}
export declare function lookupProtocolRouting(protocol: ProtocolKey): ProtocolRoutingGuidance;
export declare function listProtocolRoutingKeys(): ProtocolKey[];